As we all know, laser cutting machine has incomparable advantages in cutting metal plates. It not only has high cutting accuracy, smooth cross section without burrs, but also can achieve good results in cutting thick plates or thin plates. However, these effects are related to the focusing control of laser cutting machine. It is the principle of using SLR camera to focus and achieve better imaging effects. The laser cutting machine will focus the laser emitted from the laser into a high power density laser beam through the optical path system. The laser beam shines on the surface of the workpiece to make the workpiece reach the melting point or boiling point, while the high-pressure gas coaxial with the beam will blow away the molten or vaporized metal. The laser cutting machine replaces the traditional mechanical knife with an invisible beam, which has the characteristics of high precision, fast cutting, not limited to the cutting pattern limitation, automatic typesetting, material saving, smooth incision, low processing cost, etc., and will gradually improve or replace the traditional metal cutting process equipment. With the movement of the relative position of the beam and the workpiece, the laser cutting machine will eventually make the material form a slit, so as to achieve the purpose of cutting.
So, what is focus control? Those who are familiar with the laser cutting machine know that the laser cutting machine is used in different materials and plates of different thicknesses. In order to achieve better cutting effects, the focus of the laser beam will be set in different places, which is what we call focusing.
In the early application of laser cutting, the main focus is to rely on a manual mode to complete. Now, with the development of laser technology, the manual focusing mode has been eliminated, and automatic focusing has begun to be realized. For example, the whole series of laser cutting machines are equipped with automatic focusing function. Then, some people will say that the optical path integrated in the cutting head can be realized by changing the height of the cutting head, but the focusing function is still not available? When the cutting head is raised, the focus position is high, and when the cutting head is lowered, the focus position is low. However, the fact is that we did not imagine such a simple one.
The bottom of the cutting head is the nozzle. During the cutting process, the distance between the nozzle and the workpiece material (nozzle height) is about 0.5~1.5mm, which can be regarded as a fixed value, that is, the nozzle height will not change, so we cannot focus by controlling the lifting and lowering of the cutting head at the same time (otherwise, the enterprise cannot complete the cutting technology processing in time).
The focal length of the focusing mirror does not change, so it cannot be expected to focus by changing the focal length. If the focus position of the reflector is changed, the focus position can be changed: the focus lens is lowered, and when the focus lens is lowered and increased, the focus lens is increased. MDASH; MDASH; This is really a way of focusing. The focusing lens driving motor is used for moving up and down, and automatic focusing is realized.
Another method that can automatically focus is to set a variable curvature reflector (or adjustable mirror) before the beam enters the social focus mirror, and change the divergence angle of the reflected beam by constantly changing the curvature of the reflector, so as to change the main focus position of the enterprise.
With the automatic focusing function, the machine can automatically focus to the most appropriate position when processing workpieces of different materials and thicknesses. This can significantly improve the processing efficiency of the laser cutting machine, and the thick plate perforation time will be greatly reduced.
Therefore, for the laser cutting machine, the automatic focusing function is an important and indispensable function.